In his new position, Mitchell will have greater overall group responsibilities, working closely with WWAV group CEO Marco Scognamiglio, chief financial officer Dennis Gillespie, chairman Ian Hayworth and global data solutions CEO Thomas Funk on development of the WWAV Rapp Collins Group.
He will also take leadership on client development across the group.
Mitchell has been managing director of WWAV Rapp Collins Media since 2001.
He started in the media industry at IPC Magazines, moving to WWAV in 1990 as media manager.
He then became a partner in start-up Mansfield Lang and subsequently moved to Optimedia Direct as managing director.
Scognamiglio said: "It is essential in this increasingly fragmented media world we find new and better ways to connect with consumers and thus add value for our clients.
"This will be a major priority for us as we continue to evolve our business and Peter has the experience and the skill sets necessary to provide real passion and leadership in this area and ultimately ensure we keep ourselves and our clients ahead of the game."